Recoverable warp sizing

ABSTRACT

A polyamide warp sizing material soluble in selected organic solvents and ammoniacal aqueous media. The sizing material can be applied to the warp from an ammoniacal aqueous media and removed with an organic solvent.

nited States Patent Minkema et al.

RECOVERABLE WARP SIZING Inventors: William H. Minkema, Maple Plain; Paul D. Whyzmuzis, St. Paul, both of Minn.

General Mills Chemicals, Inc., Minneapolis, Minn.

Filed: Aug. 24, 1972 Appl. No.: 283,455

Assignee:

US. Cl 8/138, 8/18, 106/238, 117/135.5 CQ, 117/140 A Int. Cl D061 l/14 Field of Search 8/138, 18; 106/238; 117/1395 CO, 140 A References Cited UNITED STATES PATENTS 12/1947 Monsaert, Sr. 8/138 X Drelich 8/138 X Case et a]. 8/138 Primary ExaminerMayer Weinblatt Attorney, Agent, or FirmAnthony A, Juettner; Gene 0. Enockson; Elizabeth Tweedy [57] ABSTRACT 3 Claims, N0 Drawings RECOVERABLE WARP SIZING This invention relates to a process for sizing warp in which the sizing material is recoverable. More particularly, this invention relates to a process for sizing warp involving depositing a selected thermoplastic polyamide in the warp from an aqueous ammoniacal solution, removing the polyamide from the warp with a selected organic solvent and recovering the selected polyamide from the selected solvent.

BACKGROUND OF THE INVENTION Spun yarns and synthetic filaments are converted into cloth by weaving together lengths of yarn or filaments. In the weaving operation, lengths of yarn or filament are stretched in parallel positions on a loom. The lengths of yarn in this position is the warp. Alternating lengths of the warp are raised and lowered by the loom as weaving proceeds. During the raising and lowering operation, other lengths of yarn or filaments are placed between the alternating lengths of warp perpendicular to the warp and on the same horizontal plane. These lengths of yarn or filament are the werf. Because of the bending, flexing and stretching to which the warp is subjected, it must be protected by a sizing material.

The sizing and weaving process conventionally involves the following steps:

1. subjecting the warp yarn or filament to a bath of sizing material and carrier,

2. squeezing the yarn or filament to cause penetration of the sizing material and carrier into warp and removal of excess sizing material and carrier,

. drying the warp to remove the carrier, weaving the warp and werf,

. desizing the warp,

. scouring the woven material,

. bleaching the woven material,

. dyeing the woven material,

. drying the woven material, and

10. finishing the woven material.

A warp is no better than its weakest yarn. A broken yarn does not weave. The object of the warp sizing operation is to penetrate the warp with materials which will protect the warp from mechanical abrasion during weaving. A sizing material to be effective must bond to the fiber. Good sizing is not plastered on the yarn or filament but is carried into the yarn or filament by the solvent and upon subsequent drying binds the yarn or filament together in a protective envelope or cohesive yarn bundle. The surface of the yarn or filament is predominantly fiber rather than sizing. A good sizing material, therefore, must have good penetration properties, and the capability upon drying of binding to the yarn or filament and also binding together the threads of the yarn or filament. Upon drying, the sizing material forms a film. Ideally the sizing filmshould be so strong and hold the fibers so tightly in the yarn bundle that a wild thread is pulled outor broken off. The sizing film itself must be flexible and have good elongation properties to permit the necessary movement in the weaving operation. The sizing film must also be strong enough that it is not abraided off during the weaving operation. Finally it must provide a smooth surface on the yarn or filament bundle to reduce friction. In order to bond to the yarn or filament and also form strong films the sizing material must be both adhesive and cohesive. Mate- I rials which form strong films but do not bond the fiber have no value as sizing materials.

In the past and generally in the present, the application of sizing materials, the removal of sizing materials, scouring, bleaching and dyeing of yarn or filaments have been conducted using water base solutions, suspensions or emulsions. A number of warp sizing materials have been applied using water as the carrier. Starch, starch derivatives and animal glue have been used to size cotton. Polyvinyl alcohol and carboxymethylcellulose have been used to size synthetic fibers, cottons and blended yarns. In the application of sizing using a water carrier, the sizing material is dissolved or emulsified in the water. The concentration of sizing material in the carrier is generally about 5 to 20 percent by weight. The yam is passed through a bath and subsequently through squeeze rolls to wet the yarn or filament and cause penetration of the sizing material. Operating conditions are generally used so that the yarn or filament picks up about to 1 10 percent of the sizing composition by weight of the yarn or filament. Ideally about 5 to l0percent sizing material by weight of the yarn or filament is incorporated into the yarn or filament. The carrier is finally evaporated from the sizing material.

After weaving, the warp sizing material is generally removed from the cloth. That is, the yarn is desized. In

cessing. The water carrying the starch, polyvinyl alcohol or carboxymethyl cellulose from the desizing operation is generally discharged into a sewer or river. The sizing material cannot be recovered and recycled back into the system. This has created major water pollution problems. Thus far no effective method of handling this waste has been available.

Recent developments in the field of weaving have been the replacement of water in the warp sizing and desizing systems with chlorinated solvents. The chlorinated solvents have high solvent power, are chemically stable, present a range of boiling points and are generally inert in respect to fabrics. Chlorinated solvents which have been used in warp sizing operations include methylene chloride, trichloroethylene, perchloroethylene and 1,1 ,l-trichloroethane. The use of chlorinated solvents makes possible substantial advantages in processing. For example, the energy required in the drying operations is about 10 percent of that required when water is used. The desizing operation and the scouring operation, which are separate in the water systems, can be combined into one operation.

Ideally the system using chlorinated solvents is completely closed and provides for the recovery and recycling of the solvent (used for both sizing and desizing) and the sizing material itself. At the present time, the industrial changeover to the ideal system is not yet complete. The industrial facilities are still basically equipped to apply sizing materials from aqueous emulsions, suspensions or solutions. Therefore, it is 'desirable that a sizing system be developed which uses as 3 much of the existing equipment in the industrial facilities as possible and at the same time achieves the benefits of recovering the sizing material and combining desizing and scouring operations. Specifically, such a system calls for a method of sizing by means of an aqueous mediaand desizing by means of a solvent system from which the sizing material can be recovered, preferably unchanged. Obviously, in addition, all of the requirements of a good sizing operation must be met.

SUMMARY OF INVENTION i These polyamides are soluble in ammoniacal aqueous media and in selected organic solvents having solubility parameters of 9.1 to 13.9.

DETAILED DESCRIPTION OF THE INVENTION The polyamides useful in the process of this invention are amidification products of rosin acid-maleic acid, maleic anhydride or fumaric acid adducts,-polymeric fat acids and polyhexamethylene polyamine. The polyamides are somewhat acidic and have acid values of about 70 to 120. The acid value is defined as the num- ,.ber of milligrams of potassium hydroxide neutralized by the free acids present in one gram of polyamide. The determination is done by titrating the sample in hot 95 percent ethyl alcohol and using phenolphthalene as an indicator. In the practice of this invention, ammonium hydroxide is employed in the sizing solution to approximately neutralize the acidity of the polyamide.

The selected polyamides include the components recited above. A description and/or the preparation of the components is discussed below. Finally the preparation of polyamide itself is discussed in detail under the appropriate headings below.

Polyamide Components i Rosin Acid-Dicarboxylic Acid or Anhydride Adduct One of the constituents of the thermoplastic polyamides of this invention is an adduct or rosin acid and an aliphatic, unsaturated, dicarboxylic anhydride or acid selected from maleic anhydride, maleic acid, fumaric acid and mixtures thereof. The aaduct can contain from about 100 to 200 equivalent percent of the unsaturated aliphatic dicarboxylic acid anhydride to 100 equivalent percent rosin acid. Preferably the mole ratio is about one to one. Rosin acids are abietic, dihydroabietic and dehydrabietic acids. They are residues from the distillation of oleoresin obtained from Pinus palustris. They are commercially sold as gum rosin, wood rosin and tall oil rosin. One source of rosin acid is tall oil. Tall oil is a by-product of wood pulp. In the crude state it contains about 34 to 40 percent abietic acid, dihydroabietic and dehydrabietic acid, generally called the rosin acids, about 50 to 60 percent unsaturated fatty acids, generally called tall oil fatty acids, and about 5 to percent unsaponifiable material. The unsaturated fatty acids generally contain from 16 to 24 carbon atoms and predominantly monomeric, oleic and linoleic acid. The components of tall oil are commercially available as tall oil rosin acid and tall oil fatty acids. A typical commercially available rosin acidmaleic anhydride adductis commercially sold under the" trademark Arochem 404 by Ashland Chemical Co.

In general, the rosin acid-maleic anhydride, maleic acid or fumaric acid adduct is made by heating with agitation a mixture of the rosin acids and the maleic acid, maleic anhydride or fumaric acid to a temperature of about to 250C. The heated mixture is held at that temperature for about one half hour to three hours. Polymeric Fat Acid Polymeric fat acids are commercially available products. A description of polymeric fat-acids and their method of preparation may be found in U.S. Pat. No. 3,157,681 which disclosure is herein incorporated by reference. As set out in this disclosure, polymeric fat acids can result from the catalytic polymerization of ethylenically or acetylenically unsaturated monocarboxylic aliphatic acids containing from eight to 22 car bon atoms. Unsaturated aliphatic monocarboxylic acids can also be polymerized in the absence of a catalyst. Unsaturated aliphatic monocarboxylic acids having 16 to 18 carbon atoms are preferred for purposes of the present invention. Most preferred are unsaturated, aliphatic monocarboxylic acids containing 18 carbon atoms. Linoleic and oleic acids are examples of useful unsaturated aliphatic monocarboxylic acids containing 18 carbon atoms, mixtures of which are found in tall oil fatty acids.

After polymerization with or without a catalyst, the resulting mixture contains predominantly dimeric fat acids, some trimeric and higher polymeric fat acids and some unpolymerized monomeric fat acids. Typical compositions of commercially available polymeric fat acids based on unsaturated C fat acid, i.e. tall oil fatty acids, are:

C monocarboxylic acids 5-15 percent by weight;

C dicarboxylic acids 60-80 percent by weight;

C (and higher) tricarboxylic acids 10-35 percent by weight.

These mixtures may be fractionated by suitable means such as high vacuum distillation or solvent extraction techniques so as to obtain dimer acid cuts of higher concentration where necessary. For the pur-.

poses of making the selected thermoplastic polyamides useful in the present invention, the monomeric fat acids content can vary over a fairly wide range, preferably from about 5 to 20 percent by weight. Polymeric fat acids may also be hydrogenated (before or after fractionation) to reduce unsaturation. Hydrogenation is generally conducted under hydrogen pressure in the presence of a hydrogenation catalyst. It is also under stood that such other derivatives of polymeric fat acids which are capable of forming amides in reaction with a diamine, such as the lower alcohol (one to eight carbon atoms) esters of polymeric fat acids may be employed in place of the acids themselves in which the byproduct is then a lower alcohol rather than water. Polyhexamethylene Polyamine The amine component of the thermoplastic polyamides useful in the practice of this invention are the polyhexamethylene polyamines having the formula:

wherein n is an integer of 1-3.

The polyhexamethylene polyamine may consist of a mixture of various homologs in the polyhexamethylene polyamine series or may be a substantially pure compound such as bis (hexamethylene)triamine which is preferred.

Optional Co-Acids Dicarboxylic acids having the formula ll ll C-OH m R 0 C-OH wherein R is an alkylene radical containing one to eight carbon atoms can be incorporated into the polyamide for purposes of raising the melting or softening point. These di'carboxylic acids contain two to carbon atoms and include malonic, succinic, glutaric, adipic, pimelic, suberic, phthalic, isophthalic and terephthalic acids. Generally the dicarboxylic acid can be used in amounts up to about 25 equivalent percent of the total acid component. Monomeric, unsaturated fatty acids containing 16 to 18 carbon atoms, preferably 18 carbon atoms, can also be added to raise the melting or softening point of the resin. Linoleic acid, oleic acid and mixtures thereof are particularly preferred. Mixtures of linoleic and oleic acid are the major constitu-' ents'of the naturally occurring tall oil fatty acids. Tall oil fatty acids can be used in formulating the polyamides of this invention. Generally monomeric, unsaturated fatty acids can be employed in amounts up to about 10 equivalent percent.

Preparation of Polyamide To make the selected polyamides, the adduct is prepared as described above. The temperature of the adduct upon preparation is about 130 to 250C. as described above. Polymeric fat acid is added to the heated adduct. The resulting mixture is then cooled to a temperature of about 70 to 100C. and the polyhexamethylene polyamine is added. An opaque, foamcontaining paste results. The paste is heated to a temperature of about 120 to 140C. and held for a period of about to 45 minutes. The temperature is then raised to 225C. and the product is held at that temperature for a period of about 15 to 45 minutes. Vacuum may be applied if desired to withdraw volatile byproducts and to keep the resin mixture from contact with air which may cause darkening. An inert gas may be employed to avoid contact with air.

Typical useful amounts of reactants may be ex- .pteis d if lews Equivalent Percent Total Amine Polyhexamethylene polyamine 45-70 ed on total acids=l 00 wherein the amount of co-acid is greater thanzero.

Warp Sizing Process In general, the process of this invention comprises making a slightly ammoniacal aqueous solution of the above-described polyamide, depositing the selected polyamide upon a warp generally using a conventional size box, weaving the warp, after the weaving operation removing the selected polyamide from the warp with an organic solvent, separating the selected polyamide and the solvent, recycling the selected polyamide back into the sizing solution and recycling the solvent back into the desizing operation.

The aqueous sizing solution comprises from about 5 to 20 percent selected polyamide by weightand ammonium hydroxide equivalent to about to 1 10 percent of the acid value of the polyamide. The warp is passed through a bath of said ammoniacal polyamide solution. Preferably more than about 6.0 percent polyamide by weight of the warp is added onto the warp. The wette d warp is then usually passed through a squeezing roll to facilitate penetration of the selected polyamide into the fiber. After squeezing the warp is dried. The evaporation can be done at temperatures of approximately the boiling point of water. The warp then passes through the weaving operation. After weaving, the warp is desized by passing it through a hot organic solvent wash or a scouring operation using vapors of the organic solvent. Generally, the volability of the solvent used determines the temperature at which desizing is conducted. The desizing and scouring operations can be combined if desired. Once the selected polyamide has been removed from the warp, it is recovered by distilling off the solvent.

Solvents suitable for the desizing operation have solubility parameters of about 9.1 to 13.9. Solubility parameters of solvents are numerical constants that can be accurately calculated from measurable physical properties of the solvent. Such measurable physical properties include energy of vaporization, molal volume and heat of vaporation. The solubility parameter is usually designated by the Greek symbol 8. Solubility parameter can be calculated as follows:

8 (AH" RT/V) wherein AH is heat of vaporization, R is the gas constant, T is temperature in degress Kelvin and V is molal volume. This technique of calculation may be found in The Solubility of Nonelectrolytes by J. Hildebrand and R. Scott, Reinhold Publishing Corp., New York, 1924, 1936 and 1950. Naturally organic solvents which are non-injurious to the fiber must be used. Generally speaking, chlorinated hydrocarbons, fluorinated hydrocarbons and hydrocarbons themselves are non-injurious to most fabrics. Iodohydrocarbons, on the other hand, may discolor fabrics. At the present time, chlorinated organic solvents are preferred by textile manufacturers. Representative of such solvents are trichloroethylene (solubility parameter 9.3, b.p. 87C.), 1,1,2-trichloroethane (solubility y rameter 9.6, b.p. 114C.) and methylene chloride (solubility parameter 9.7, b.p. 39C.). The appropriate sol- The selected polyamides employed in the process of this invention are uniquely qualified as sizing materials. They are soluble in aqueous ammoniacal solution and also flexible and easily move through the weaving operation. In addition, they are remarkably adhesive and firmly bond yarn fibers and filaments together.

For purposes of illustrating the invention, a specific example of a warp composition useful for warp sizing is set out below. i

EXAMPLE This example illustrates the properties of the selected polyamide as a sizing composition upon typical warps.

The selected polyamide was made using the following equivalent proportions:

Components Equivalents Tall oil rosin acid 0.228 Maleic anhydride 0.204 Polymeric tall oil fatty acids 0.!9 Monomeric tall oil fatty acids 0.075 Adipic acid 011 Bis(hexamethylene)triamine 0.433

The procedure for making the polyamide was as follows. The tall oil rosin acid and maleic anhydride were charged into the reactor vessel and heated carefully to 200C. with stirring and under nitrogen gas. The mixture was held at that temperature for a period of one hour. The polymeric tall oil fatty acids, monomer tall oil fatty acids and the adipic acid were then added with stirring. The mixture was then cooled to about 80C. and the bis(hexamethylene)triamine was added. The resulting paste was heated to a temperature of 140C. and held at that temperature for a period of 30 minutes. The temperature of the mixture was then raised to 225C. The mixture was held at that temperature for a period of 30 minutes under nitrogen. A vacuum of about 10 millimeters was applied to the mixture for about 10 minutes. The mixture was cooled to 200C, the vacuum was broken with nitrogen and the product was discharged.

The above polyamide was dissolved in amounts of 10 percent by weight in an aqueous solution containing 0.75 percent ammonium hydroxide. The polyamide was then tested for its abrasion resistance and tensile strength using the conventional testing procedures described below. For purposes of comparison, a conventional warp sizing composition of l2 percent starch (Penick and Ford Penferd Gum 280) by weight and 88 percent water by weight was included in the testing. The starch was cooked for minutes at a temperature of"'95C.

The yarns used for illustration were unsized blue denim yarn of /40 polyester/cotton blend average diameter 0.0032 inch. The yarns were cut into 100 cm. lengths. Each length was passed through a beaker containing one of the sizing compositions. After being passed through the sizing compositions, the lengths of yarn were squeezed to remove excess sizing material. The lengths of yarn were partially dried with an air gun and finish dried'at room temperature by ambient air.

The dried yarn was tested for abrasion resistance and tensile strength. The tensile strength testing was done using a TTC lnstron. This instrument is equipped with clamps which hold the ends of the yarn. The clamps are moved apart at a given and constant rate by increasing the force moving the clamps. The force being applied when the yarn breaks is the measurement of tensile strength. The lengths of yarn were stretched at a rate of 2 inches per minute. Five lengths of each of the two yarns sized with the polyamide and ten lengths of the two yarns sized with starch were stretched. The measurements in each series were averaged. Relative humidity during the testing was 50 percent. The results are shown in the table.

The abrasion resistance of the yarn was tested using a C.S.l. Universal Wear Tester having a one inch stroke and 256 strokes (rubs)/minute, microscope slides and clamps to weight the ends of the yarn. The microscope slides used were trident Supreme microscope slides, Central Scientific Cat. No. 266-999, 1.1 to 1.3 mm. thickness, three inches by one inch in size. The clamps used to weight the yarn weighed 13.97 g. for the denim yarn and 33-24 g. for the white cotton yarn. In general, the test consists of moving the sized yarn back and forth across the edge of the microscope slide until it wears to the point of breaking. in the calibrated testing one end of the length of yarn is clamped into the Universal Wear Tester. The other end of the yarn is weighted with a clamp. A microscope slide is positioned below and in front of the Universal Wear Tester so that the angle from the horizontal axis if 15. The microscope slide itself is tilted at a 4 angle away from the Universal Wear Tester. The length of yarn is draped over the microscope slide with a weighted end hanging free. The Universal Abrasion Tester pulls the yarn to ward it across the edge of the microscope slide. then releases the tension and the yarn is pulled back across the microscope slide edge by the weight of the clamp.

The present test involved making five determinations each on the two yarns sized with polyamide'a'n'd six determinations on each of the two yarns sized with starch.

The results of each series were averaged and the results are shown in the table. The determinations were made at percent relative humidity and 73F. temperature. The microscope slide was changed before each series was begun.

Table Testing Results TENSlLE TESTING Sizing Yarn by Average Number of Rubs Improvement Average Grams 7! Improvement Weight To Fuzz To Break Over Unsized To Break Yarn Over Unsized Add-On Sized Unsized Sized Unsized Yum Sized Unsized Yum Yarn Yarn Yarn Yarn To Fuzz To Break Yarn Yarn Polyzimide Denim 6.l l9 l5 l 18 81 27 46 935 920 L6 Polyamide Cotton 3.2 l5 I6 28 29 6 -4 196 176 HA Polyamide Cotton l3 l7 22 25 24 -l 2 222 176 31.8

Starch Denim 24 i5 lOO 77 60 3O l073 920 [6.6

Starch l2. l7 84 93 24 l() I083 920 l7.6

Denim 3 2l The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A process for sizing and desizing warp comprising:

x. polymeric fat acid resulting from the polymerization of unsaturated monocarboxylic acid having 16 to 18 carbon atoms,

y. a coacid selected from dicarboxylic acids having the formula ll II C-OH R ll I wherein R is an alkylene radical containing one to eight carbon atoms and monomeric unsaturated fatty acids containing 16 to 18 carbon atoms, and monomeric unsaturated fatty acids containing 16 to 18 carbon atoms, and

wherein n is an integer of 1 to 3, and wherein the amidi ication reaction was accomplished by heating the components from a temperature of about C. to 225C. and the amiditication product has an acid value of about 70 to 120, B. washing the warp with an organic solvent having a solubility parameter of about 9.1 to 13.9 selected from the group consisting o1- trichlorocthylenc, 1,1,2-trichloroethanc and methylene chloride, whereby dissolving the amidification product, and removing said amidification product from the warp, and C. distilling the solvent from the amidification product. 2. The process of claim 11 wherein said amidification product has the following composition:

Polyhexamethylene polyamine 45-70 based upon total acid wherein the total amount of co-acid is greater than zero. 4

3. The process of claim 2 wherein the polyhexameth ylene polyamine is bis(hexamethylene)triamine.

=l l l $22530 v UNITED STATES, PATENT oFFICE CERTIFICATE GI CORRECTION Patent No. 3,841,833 Dated October 15,1974

Inventor) William H. Minkema and Paul D. Whyzmuzis It is oe-ftified that error appears in the above -i dentified patent and that s'aidfLettexs Patent are hem-shy corrected asshown below:

Column 3; line 52, "aaduct" should be add uct 1 Column 6 line 44 "6 (AH RT/V should be 6 A3 ET/v Column 8 line 4 0, "if" should be is Si'smedand sealed this 33st day of December ??74.

(SEAL) Attest:

MCCOY H. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. A PROCESS FOR SIZING AND DESIZING WARP COMPRISING A. DEPOSITING FROM AN AQUEOUS SIZING SOLUTION CONSISTING ESSENTIALLY OF ABOUT 5 TO 20 PERCENT AMIDIFICATION PRODUCT BY WEIGHT AND AMMONIUM HYDROXIDE EQUIVALENT TO AOUT 90 TO 110 PERCENT OF THE ACID VALUE OF THE AMIDIFICATION PRODUCTS, SAID AMIDIFICATION PRODUCT CONSISTING ESSENTIALLY OF: W. AN ADDUCT OF ROSIN ACID AND AN UNSATURATED DICARBOXYLIC ACID OR ANHYDRIDE SELECTED FROM MALEIC ACID, MALEIC ANHYDRIDE AND FUMARIC ACID WHEREIN THE UNSATURATED DICARBOXYLIC ACID IS PRESENT IN AMOUNTS OF ABOUT 100 TO 200 EQUIVALENT PERCENT TO 100 EQUIVALENT PERCENT ROSIN ACID, X. POLYMERIC FAT ACID RESULTING FROM THE POLYMERIZATION OF UNSATURATED MONOCARBOXYLIC ACID HAVING 16 TO 18 CARBON AOMS, Y. A COACID SELECTED FROM PICARBOXYLIC ACIDS HAVING THE FORMULA
 2. The process of claim 1 wherein said amidification product has the following composition:
 3. The process of claim 2 wherein the polyhexamethylene polyamine is bis(hexamethylene)triamine. 